Reciprocating pumps are often employed to produce many oil wells. Typically, the pump comprises a plunger with valves that strokes within a barrel at the lower end of a string of production tubing. A string of sucker rods extends from the plunger to a lifting mechanism at the surface. The lifting mechanism strokes the rods to move the plunger in an up stroke and a down stroke.
Some wells have inclined and even horizontal lower portions. The inclined portion connects to a vertical portion of the well at a bend. Placing the pump within the inclined section of the well can present problems. The upward and downward movement of sucker rods at the bend in the tubing creates wear on the rods as well as the tubing.
Another common type of pump is an electrical submersible pump. This type of pump has a motor, normally electric, coupled to the pump. Electrical power may be supplied over a power cable that is strapped alongside the production tubing. The pump is normally a rotary type, such as a centrifugal pump or a progressing cavity pump. Electrical submersible pumps can be installed in an inclined section of a well as there will be no reciprocating movement of any of the components. Generally, an electrical submersible pump is more expensive than a reciprocating type pump for the same well.